By Steven Kotler — SingularityHub
For most of the last century, the study of emotions was not considered serious science. The problem was subjectivity. Science is objective, rigorously objective. Emotions, though, are internal states, so the only way to study them is through subjective inference (essentially asking people to report how they feel). But — because people lie, because we often misinterpret our emotions and because comparisons between subjects, that is the depth of my anger versus your anger, is impossible to measure—there’s no objective data to be found.
Thus, until recently, the topic was taboo.